Kim’s team reviewed 18 big, solid scientific studies published from 1970 to 2016 covering more than 2 million people who were followed for an average of 18 years.
“There was no association between multivitamin and mineral supplementation and cardiovascular disease mortality,” they wrote in their report, published in the American Heart Association’s journal Circulation: Cardiovascular Quality and Outcomes.
“It has been exceptionally difficult to convince people, including nutritional researchers, to acknowledge that multivitamin and mineral supplements don’t prevent cardiovascular diseases,” Kim said.
“I hope our study findings help decrease the hype around multivitamin and mineral supplements and encourage people to use proven methods to reduce their risk of cardiovascular diseases — such as eating more fruits and vegetables, exercising and avoiding tobacco.”
Americans routinely ignore this advice and gobble up supplements. More than half of Americans take supplements, according to the Centers for Disease Control and Prevention, spending $12 billion a year on them.
And despite strong evidence that eating five to 10 servings of fruits and vegetables a day reduces the risk of cancer, heart disease, Alzheimer’s and a range of other diseases, just 13 percent of Americans meet this goal, the CDC found.
Instead, people believe that they can make up for poor diets with supplements — something that has been disproven in several studies.
Dr. Paul Offit of Children’s Hospital of Philadelphia, who criticizes the supplement industry in his book “Do You Believe in Magic?: The Sense and Nonsense of Alternative Medicine,” notes that some supplements are harmful.
Vitamin A, for example, can cause liver damage if taken in high amounts. One study found that too much vitamin E may raise the risk of prostate cancer. And one study of 40,000 women found a slightly higher risk of death in women who took supplements.
Yet another found that calcium might damage the heart.
But even doctors mistakenly recommend vitamin pills.
“Multivitamins are often recommended by well-intentioned physicians,” Alyson Haslam and Dr. Vinay Prasad of the Oregon Health and Science University’s Knight Cancer Institute wrote in a commentary.
“Unfortunately, the results from a variety of previous studies do not support the practice of multivitamin supplementation for cardiovascular disease and mortality.”
This includes fish oil supplements. The American Heart Association has separate recommendations on fish oil supplements based on studies showing that they don’t reduce the risk of heart disease for average people.
Prescription fish oil supplements may help some people with certain specific heart disease risks or conditions, the Heart Association says.
Otherwise, food is the best source of nutrients.
“Eat a healthy diet for a healthy heart and a long, healthy life,” Dr. Eduardo Sanchez, the American Heart Association’s chief medical officer for prevention, told NBC News.
“There’s just no substitute for a balanced, nutritious diet with more fruits and vegetables that limits excess calories, saturated fat, trans fat, sodium, sugar and dietary cholesterol.”